Two case studies are reviewed in this paper--one involving pH control with carbon dioxide and the other with ammonia. The equipment and benefits associated with this approach are also discussed. Both carbon dioxide and ammonia eliminate the possibility of over treating and minimizing solids loading, unlike sulfuric acid and lime. No extraneous maintenance or monitoring equipment is required. Reduction of pH with carbon dioxide is an efficient and safe means to achieve this objective. Carbon dioxide has many advantages when compared to sulfuric acid in both precision, safety and overall cost. Elevation of pH with ammonia is a practical and safe means, when precautions are followed, to accomplish this purpose. Ammonia as compared to caustic lime by cost, solubility, operating and maintenance costs, producing very little solids to be removed and pound-for-pound to neutralize sulfuric acid; Ammonia gas is very competitive.